1. Field of the Invention
The present invention relates to group communication in communications systems providing group service.
2. Description of the Related Art
One special feature offered in mobile communications systems is group communication. The term “group”, as used herein, refers to any logical group of two or more users intended to participate in the same group communication. One example of group communication is a group call, which is a call in which all participants may take turns to speak and to listen to each other. The same user may be a member in more than one group. Typically, the members of the group belong to the same organization, such as the police, the fire brigade, a private company, etc. Also, typically, the same organization has several separate groups, i.e. sets of groups. Even private persons might want to have talk groups, such as hobby groups, sport groups, etc.
A group communication may be used, for example, by small business users for a more frequent job-related communication during a working day within the same work group, either inside the company or within some business community. They would benefit from information on other group members, such as presence information, and especially summarized information on group members. For example, information on how many group members are logged into a group may be useful when a user has to decide whether to make a group call or “individual” call/calls. If only one other member is reachable via the group, it is probably more convenient to make an individual call instead of a group call. However, there is no summarized information on other group members available for the time being and no mechanism to provide such information exists in systems providing group communication.
One possible solution is to connect the communications system providing group communication to a presence server and change the groups into groups provided by presence service as described in the Wireless Village (WV) initiative. Presence information means information related to the user's identity, attributes and ability/willingness to communicate at a particular moment. Examples of presence service are disclosed e.g. in version 1.1 specifications for presence attributes, features and functions and system architecture model of the Wireless Village initiative or provided by wireless AOL® Instant Messenger™ (AIM) service or Enterprise AIM® service. The Wireless Village initiative is a program of the IEEE Industry Standards and Technology Organization (IEEE-ISTO), and has now joined the OMA (Open Mobile Alliance) where presence service specifications are defined in an IMPS working group.
However, these WV groups are chat groups using only messaging services, not providing essential group communication features, such as speech calls, traffic discipline, group prioritizing, etc. Furthermore, not even the presence service provides summarized group member information. For example, the number of chat group members has to be calculated manually.